Crash Outcome Data Evaluation System (CODES): An Examination of Methodologies and Multi-State Traffic Safety Applications

This report provides a summary of recent technical work in the Crash Outcome Data Evaluation System (CODES), a program facilitated by the National Highway Traffic Safety Administration (NHTSA). CODES involves a statistical methodology to augment State crash data with medical outcome data using probabilistic linkage. In 2013, NHTSA transitioned the CODES program to full State autonomy. This two-part report comprises the final technical report from the CODES Technical Resource Center at the Utah CODES project. Part one provides information on the probabilistic linkage methodology employed by CODES, and addresses related topics including other types of linkage, alternative linked data sets, match probabilities, and missing data imputation; and part two reports on demonstration projects pooling multi-state standardized data for four topics relevant to traffic safety.